Taking all-terrain vehicle (ATV) as an example, an ATV typically includes front wheels and rear wheels suspended on a front end and on a rear end, respectively, of a body frame. Handlebars and a seat are mounted on the frame. A power unit such as an engine is also mounted on the frame and generates the power required to propel the ATV. A transmission is provided to transfer the power generated by the engine to the front wheels, the rear wheels or both the front and rear wheels to drive the ATV. Typically, the ATV operator moves the transmission to a neutral or geared position when the ATV is not in use, the geared position being preferred to immobilize the ATV.
The transmission of an ATV typically includes a reverse gear to back up the vehicle when required as is standard in many vehicles. The reverse gear of the transmission of an ATV, as in many other straddle-type vehicles, is accessible by bringing the transmission down from the neutral position to the 1st forward gear and shifting down once more into the reverse gear. The shifting interface with the operator of an ATV is typically via a shift pedal with a clutch handle on the left-hand side of the handle bars.
In operation, the All Terrain Vehicle (ATV), as its name implies, is often used over rough terrains. In rough terrains, when the operator of the ATV is downshifting into first gear or into the neutral position, there is a possibility that the operator accidentally shifts down into the reverse gear while the ATV is still moving forward. This could damage the gearbox.
Reverse gear locking mechanism exist and have been installed on ATV in order to prevent accidental shifting into reverse gear while the ATV is still going forward. Prior art reverse gear locking mechanism typically consist of actuated lock shafts mounted parallel to the shift drum of the transmission of the ATV which are moved back and forth into and out of engagement with the shift drum. The drawback of the layout of those actuated lock shafts in parallel with the shift drum and the corresponding movement of the actuated lock shafts parallel to the axis of rotation of the shift drum, is that space is very limited in this area aligned with the shift drum for positioning the actuator (lever or others) outside the transmission and for actuating the lock shaft. The gear selector is typically aligned with the shift drum on one side of the transmission and the chain sprocket on the other side of the transmission.
Thus, there is a need for an improved mechanism to prevent accidental shifting into reverse gear.